While theory strongly suggests that restricting development rights should reduce land prices, empirical evidence of this effect has been notoriously hard to obtain. Indeed, largely based on this difficulty a Congressional committee has recently recommended that tax benefits for such restrictions be severely curtailed. We collect data on 131 land transactions in South Central Wisconsin, including 19 cases of developmentrestricted parcels. When we use the whole sample to estimate the impact of conservation easements we replicate the results of Nickerson and Lynch (2001), finding a negative but statistically insignificant effect. However we then show that when the sample is appropriately restricted to a more homogenous group of land parcels, our ability to detect an effect increases dramatically. In particular, for vacant agricultural land we find a statistically significant negative impact of conservation easements that ranges up to 50% of land values.